1. Field of Invention
The present invention relates to a transmittal mechanism for a support apparatus. More particularly, the present invention relates to a downward mechanism for support pins.
2. Description of Related Art
For both semiconductor integrated circuits and flat display panels, many reactors used in the manufacturing process are designed as removable reactors of single or multiple-stacked type. Removable reactors and the main body of machines or removable reactors and the transmittal mechanisms, support pins, can be disengaged. The transmittal mechanism of the support pins for supporting a work piece, such as a silicon substrate used in semiconductor integrated circuits or a glass substrate used in flat display panels, is an indirect transmittal mechanism and can be disengaged from the support pins.
Conventionally, a substrate is transported into or out of a reactor by transmittal mechanism using support pins. FIGS. 1A–1E are diagrams showing the whole transmittal action performed by a transmittal mechanism using support pins for a conventional chemical vapor deposition reactor. In FIG. 1A, a substrate 100 is carried by a robot 110 and prepared to enter a reactor. A bottom plate 120 of the reactor has some holes 130 therein to allow support pins 140, which have bases 150 thereunder, to enter the reactor through holes 130. In FIG. 1B, the robot 110 transports the substrate 100 into the reactor, and an elevator (not shown in the figure), shores up the bases 150 to lift the support pins 140 up. The support pins 140 penetrate the bottom plate 120 through the holes 130 to raise the substrate 100. In FIG. 1C, the robot 110 moves out of the reactor, and the substrate 100 is left in the reactor. The elevator then descends; the support pins 140 can thus be lowered by the weight of the support pins 140 and the bases 150.
In FIG. 1D, a thin film is formed on the substrate 100 by chemical vapor deposition, and then the elevator then rises to shore up the bases 150 and lift the support pins 140. The substrate 100 is hence raised again. Then, the robot 110 enters the reactor at the downward direction of the substrate 100 to load the substrate 100. In FIG. 1E, the robot 110 carries the substrate 100 out of the reactor. The elevator then descends to lower the support pins 140.
During the process of transporting substrate 100 into and out of the reactor, since the support pins 140 cannot be fixed to the elevator, the support pins 140 and bases 150 are not lowered directly by the elevator. Therefore, the support pins often do not descend smoothly, and the substrate 100 is thus often fragmented.
In Taiwan Utility Model Patent Number 521,861, two steel lines are used to improve the problem described above. However, the steel lines are often deformed, and the bases underneath the support pins are thus not buckled. Consequently, the support pins still do not descend smoothly.